Growing up in a close-knit family in Singapore, Desiree Koh cherished the Christmases she spent with her parents and brother. Even after she immigrated to the United States nine years ago as a college student, her family joined her in Chicago for the holidays.

But in 2001 their vacation schedules no longer meshed. Ms. Koh, now a publicist, found herself on her own, 9,000 miles from her family on Dec. 25.

"It's a little jarring the first year alone without family for the holidays," she says. "I was a little bit at a loss."

As the strains of "I'll Be Home for Christmas" fill the December air, a record number of Americans - 63.5 million, according to AAA - are crowding planes, trains, and cars to share the holidays with loved ones. At the same time, millions of less-visible celebrants, like Koh, are preparing to observe Christmas on their own.

Culture-watchers point to a variety of sociological changes that are increasing the ranks of those spending what Koh calls "a holiday for one." These include growing numbers of immigrants separated from relatives by oceans, high divorce rates, military duty in Iraq, 24/7 work schedules, and a large single population. The Census Bureau reports that 49.8 percent of American households are headed by single people.

For Ms. Koh, who is Chinese, this will be her fourth Christmas alone. Typically, friends invite her to share Christmas Eve dinner. But, she says, "I never want to impose on others' family time together on Christmas Day." So she puts a "special spin" on the holiday in Chicago's Chinatown.

"When everyone is opening presents and sipping egg nog, I'm indulging in Chinese tea and dim sum," Koh says. "The bustle of my favorite restaurant, sharing tables with others who are also spending the day alone, and enjoying some 'comfort food' cheers the spirits nicely - not as well as if my family was around, but at least I still feel like part of a community."